Currently, we only support 52-bit virtual addressing on 64k pages
configurations, and in all other cases, vabits_actual is guaranteed to
equal VA_BITS (== VA_BITS_MIN). So get rid of the variable entirely in
that case.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
arch/arm64/include/asm/memory.h | 4 ++++
arch/arm64/kernel/head.S | 7 +++----
arch/arm64/mm/mmu.c | 2 ++
3 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 2f1a48be11cf..c989f6bf5426 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -174,7 +174,11 @@
#include <linux/types.h>
#include <asm/bug.h>
+#if VA_BITS > 48
extern u64 vabits_actual;
+#else
+#define vabits_actual VA_BITS
+#endif
extern s64 memstart_addr;
/* PHYS_OFFSET - the physical address of the start of memory. */
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 44e2e39046a9..836237289ffb 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -283,19 +283,18 @@ SYM_FUNC_START_LOCAL(create_idmap)
adrp x0, idmap_pg_dir
adrp x3, _text // __pa(_text)
-#ifdef CONFIG_ARM64_VA_BITS_52
+#if (VA_BITS > 48)
mrs_s x6, SYS_ID_AA64MMFR2_EL1
and x6, x6, #(0xf << ID_AA64MMFR2_LVA_SHIFT)
mov x5, #52
cbnz x6, 1f
-#endif
mov x5, #VA_BITS_MIN
1:
adr_l x6, vabits_actual
str x5, [x6]
dmb sy
dc ivac, x6 // Invalidate potentially stale cache line
-
+#endif
/*
* VA_BITS may be too small to allow for an ID mapping to be created
* that covers system RAM if that is located sufficiently high in the
@@ -725,7 +724,7 @@ SYM_FUNC_START(__enable_mmu)
SYM_FUNC_END(__enable_mmu)
SYM_FUNC_START(__cpu_secondary_check52bitva)
-#ifdef CONFIG_ARM64_VA_BITS_52
+#if (VA_BITS > 48)
ldr_l x0, vabits_actual
cmp x0, #52
b.ne 2f
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 20dd95a750bc..8933d4f72427 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -45,8 +45,10 @@
u64 idmap_t0sz = TCR_T0SZ(VA_BITS_MIN);
+#if (VA_BITS > 48)
u64 __section(".mmuoff.data.write") vabits_actual;
EXPORT_SYMBOL(vabits_actual);
+#endif
u64 kimage_voffset __ro_after_init;
EXPORT_SYMBOL(kimage_voffset);
--
2.30.2
